Lubrication device for an automatic transmission

ABSTRACT

A lubrication device for an automatic transmission adapted to change the lubrication of both taper roller bearings rotatably supporting the output shaft of the automatic transmission between the automatic transmission case and torque converter housing. The disclosed device promotes a smooth lubrication in relation to both taper roller bearings even when the operation oil temperature is low and thus improves the durability of the taper roller bearings.

FIELD OF THE INVENTION

[0001] The present invention relates to a lubrication device for an automatic transmission, and more particularly, to a lubrication device for transmission taper roller bearings.

BACKGROUND OF THE INVENTION

[0002] In a conventional automatic transmission, the output shaft is supported by at least first and second taper roller bearings. In order to provide smooth operation and long life, lubrication is provided to the bearings. Generally, lubrication is provided through passages in the transmission/torque converter housing; flowing first to one bearing and subsequently, upon filling the oil passage, to the other bearing.

[0003] As long as there is a sufficient supply of oil, both bearings are properly lubricated. However, when the viscosity of the oil is relatively high, before the engine and oil temperature rises sufficiently to thin the oil, adequate flow to the second bearing may not be supplied. Thus, a problem may arise with the lubrication of the second bearing, even when there is a sufficient volume of oil and the first bearing is properly lubricated. Such problems can result in the generation of eccentric friction and shortened life of the bearing.

SUMMARY OF THE INVENTION

[0004] The present invention provides a lubrication device for an automatic transmission employing forced infusion and dispersion to ensure an adequate supply of oil through centrifugal force. The invention avoids decrease in lubrication performance resulting from a lack of mobility due to low lubrication oil temperature, thereby maximizing the durable life of taper roller bearings. Thus, in a preferred embodiment of the present invention, a first lubrication oil passage is formed inside a torque converter housing. A second lubrication oil passage communicates with the first lubrication oil passage within an output shaft rotatably supported via first and second taper roller bearings between the torque converter housing and the automatic transmission case.

[0005] The first lubrication oil passage is provided at an inlet thereof with a first cap seal member equipped with an orifice. The second lubrication oil passage is provided at an inlet thereof with a second cap seal member equipped with a plurality of through holes. Thus, oil ejected under high pressure from the orifice of the first cap seal member passes or is dispersed through the plurality of through holes of the second cap seal member, thereby promoting the lubrication of the first and second taper roller bearings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] For fuller understanding of the nature and objects of the invention, reference should be made to the following detailed descriptions taken in conjunction with the accompanying drawings in which:

[0007]FIG. 1 is a sectional view partially illustrating an output shaft area supporting the transfer driven gear of an automatic transmission and lubrication oil passages and lubrication device mounted thereto according to an embodiment of the present invention;

[0008]FIG. 2 is a perspective view illustrating mounted areas of the taper roller bearings mounted at the torque converter housing illustrated in FIG. 1; and

[0009]FIG. 3 is a plan illustrating through holes formed in the second cap seal member illustrated in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0011] As shown in FIG. 1, both ends of output shaft 12, carrying a transfer driven gear 10, are rotatably supported by a first taper roller bearing 18 and a second taper roller bearing 20. The bearings are respectively secured to torque converter housing 14 and automatic transmission case 16. Outer races 18 a and 20 a, of the first and second roller bearings 18 and 20, are respectively secured to the torque converter housing 14 and the automatic transmission case 16. Inner races 18 b and 20 b thereof are respectively fixed at both ends of the output shaft 12. Taper rollers 18 c and 20 c are mounted in a rolling fashion between the outer races 18 a and 20 a and the inner races 18 b and 20 b. The outer race 18 a of the first taper roller bearing 18 is centrally fixed at a boss 14 a protrusively formed at the torque converter housing 14.

[0012] The torque converter housing 14 is preferably formed with a first lubrication oil passage 22. Passage 22 bends approximately at a right angle to pass through the walls of the housing 14 and opens at a longitudinal end thereof toward the output shaft 12. The output shaft 12 includes a centrally formed, second lubrication oil passage 24 running lengthwise through the shaft.

[0013] The first and second lubrication oil passages 22 and 24 are arranged to communicate in an area adjacent the torque converter housing 14. Oil flow is thus provided between gap 26, formed between the output shaft 12 and the torque converter housing 14, and gap 26′, between the output shaft 12 and the automatic transmission case 16. At an inlet of the first lubrication oil passage 22 is formed at the torque converter housing 14. A first cap seal member 40 is centrally equipped with an orifice. A second cap seal member 42, equipped with a plurality of through holes 42 a at the inlet of the second lubrication oil passage 24, is disposed within oil passage 24 in shaft 12.

[0014] The first lubrication oil passage 22 is formed in boss 14 b, protruding from the wall of the torque converter housing 14. The first lubrication oil passage 22 is configured to permit a smooth transition along first capsule member 40, mounted at the inlet side of the first lubrication oil passage 22. Boss 14 b may be provided when the thickness of the member defining the torque converter housing 14 is insufficient for installation of the first cap seal member 40.

[0015] As shown in FIG. 3, the plurality of through holes 42 a at the second cap seal member 42 are concentrically and radially formed, each being spaced apart from each other in the center of the member 42 in varying distances. A portion of high-pressure oil having passed the orifice 40 a of the first cap seal member 40 is infused into the gap 26 formed between one end of the output shaft 12 and the torque converter housing 14. The balance of the oil is introduced into the gap 26′ defined between the other end of the output shaft 12 and the automatic transmission case 16, thereby promoting an equal distribution of the operational oil.

[0016] As a result, the oil discharged by the oil pump (not shown) initially passes through first lubrication oil passage 22 formed in boss 14 b on the torque converter housing 14. Oil is then ejected towards one end of the second lubrication oil passage 24 disposed at the output shaft 12 through the orifice 40 a centrally formed in the first cap seal member 40 mounted at the inlet side of the first lubrication oil passage 22.

[0017] Oil injected toward the second lubrication oil passage 24 at the output shaft 12 is ejected through the orifice 40 a, and is thereby discharged under high pressure such that part of the oil thus ejected hits the front side of the second cap seal member 42. The oil is thereafter dispersed and infused into the gap 26, promoting lubrication of the first taper roller bearing 18. The balance of the oil passes through holes 42 a in the second cap seal member 42 and again passes through the second lubrication oil passage 24 to be introduced into the gap 26′, thereby promoting lubrication of the second taper roller bearing 20.

[0018] In one lubrication method according to the invention, high pressure oil passes the orifice 40 a at the first cap seal member 40 and is supplied respectively to the gaps 26 and 26′ formed at both ends of the output shaft 12 by way of forced infusion and dispersion via the second cap seal member 42. The present invention thereby promotes smooth lubrication of the first and second taper roller bearings 18 and 20 rotatably supporting both ends of the output shaft 12. Thus, the first and second taper roller bearings 18 and 20 rotatably supporting both ends of the output shaft 12 are smoothly lubricated even before the oil temperature is sufficient to recover mobility, thereby preventing eccentric friction of the bearings and maximizing the durable life of the bearings. 

What is claimed is:
 1. A lubrication device for an automatic transmission, comprising: a first lubrication oil passage formed inside a torque converter housing; a second lubrication oil passage disposed within an output shaft and communicating with the first lubrication oil passage, wherein the output shaft rotatably supported via first and second taper roller bearings between the torque converter housing and a case of the automatic transmission; a first cap seal member equipped with an orifice at an inlet of said first lubrication oil passage; and a second cap seal member equipped with a plurality of through holes at an inlet of the second lubrication oil passage, wherein the operational oil ejected under high pressure from the orifice of the first cap seal member is dispersed through the plurality of through holes of the second cap seal member, thereby promoting the lubrication of the first and second taper roller bearings.
 2. The device as defined in claim 1, wherein the torque converter housing defining said first lubrication oil passage is integrally formed with a boss expanded in thickness thereof for installation of said first cap seal member.
 3. The device as defined in claim 1, wherein the plurality of through holes of said second cap seal member are concentrically and radially arranged, each being spaced apart from each other in varying distances.
 4. A lubrication device for taper roller bearings supporting an output shaft extending between a torque converter housing and automatic transmission case, said device comprising: a first lubrication passage defined in the torque converter housing, said first passage having an inlet; a second lubrication passage defined in the output shaft and communicating with said first passage, said second passage having an inlet; a first cap seal member disposed over said first passage inlet and defining an orifice therethrough; and a second cap seal member disposed over said second passage inlet and defining a plurality of holes therethrough; wherein said first cap seal member orifice is configured to eject oil at high pressure and said second cap seal member is configured to disperse said oil through said plural holes to a second of said taper roller bearings. 